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How To Shock A Lay Z Spa – A Simple Guide & Dose Calculator

First-time Lay Z Spa owners may find their new hot tub maintenance routine to be something of a shock, but don’t worry, shocking your hot tub is actually pretty straightforward.

Alongside balancing your pH levels and regularly changing your filter cartridges, Chlorine-based shock treatments are an essential part of any basic hot tub care, helping to prevent nasty germs and bacteria from building up in your Lay Z Spa’s water.

Shock dosing is usually performed with either chlorine granules or bromine. Still, whichever you choose, when shocking your hot tub, the general methodology will remain the same, so without further ado, let’s find out how to shock a Lay Z Spa Inflatable hot tub!

How To Shock A Hot Tub For The First Time

a person testing the water in a hot tub

1: Check your PH level.

Before beginning any Lay Z Spa shock treatment be it a Chlorine or non Chlorine shock dose, you must first test your spa’s water chemistry. Whether you’re using chlorine or bromine, the hot tub chemical’s ability to work correctly will depend on the water’s pH balance.

Both are twice as effective when your spa water is at a pH level between 7.2-7.6 as they are in any other range, so use a test strip to check your pH before moving to the next step and shocking your hot tub.

2: Chlorine or bromine?

Your spa chemicals of choice will depend on which hot tub sanitiser you use. If you use chlorine tablets, you’ll need to use chlorine granules. If you use bromine tablets, we think you get the picture!  This guide explains how many chlorine tablets a Lazy Spa needs and how to do it.

Chlorine shock is the most popular choice, as chlorine will destroy any organic contaminants in the spa water and kill bacteria very quickly, with the added benefit of turning any “dead” chlorine sanitiser still in your spa into a gas that can escape the water’s surface.

The main drawback, however, is the strong chlorine smell, which is why some Lay Z Spa owners opt to use Bromine instead when shock dosing.

There are also non-chlorine shock alternatives and mineral-based sanitisers for shocking your hot tub. A non Chlorine shock dose can be useful if you have sensitive skin, but they’re not quite as effective. We recommend using Clearwater Chemicals chlorine granules where possible, as they’ve been designed specifically for the Lay Z Spa hot tub brand! 

3: Dissolve your chemicals

a person adding chemicals to a hot tub

Fill a bucket with some hot tub water and begin to dissolve your Clearwater chlorine granules into it; always remember to wear gloves when handling spa chemicals!

The general measurements will be similar, depending on your water capacity whether you’re using Clearwater’s Chlorine granules or Bromine.

We’ve found that about one teaspoon (approx 5g) of Clearwater Chlorine granules per every 250-300L of warm water that your Lay Z Spa holds is a good rule, which seems to ring true with both Lay Z Spa and Clearwater’s own recommendations. 

Remember, never add water to chemicals. Always add your chemicals to water! 

4: Add chemicals to your hot tub.

Begin to add your dissolved sanitiser chemicals to the main body of hot tub water, remembering to keep track of how much chemical has been added to the mixture.

You’ll want about one teaspoon of granules for every 250-300L of hot tub water; too little and you’ll fail to perform an effective shock dose; too much will result in the Chlorine levels being too high which will oversaturate the hot tub water!

5: Run the pump.

You can now switch on the circulation pump to help distribute the chemicals evenly throughout your Lay Z Spa hot tub.

It’s best to switch on the filtration system but leave the air jets switched off, as this will allow the solution to move through the water without agitating the chemicals too much. 

Too much movement can result in the chemicals turning into a gas prematurely, and failing to properly treat the organic compounds in the water! 

6: Allow for resting time.

Leave the hot tub filtration system powered on for around an hour with your Lay Z Spa’s cover removed. This will give the chemicals time to work and provide enough ventilation for any escaping gasses to dissipate safely. 

After around an hour, switch off the filtration system and leave your Lay Z Spa for a further 15-20 minutes with the cover of the hot tub removed; this will allow the remaining gasses to escape.

You can now pop the hot tub cover back on and allow the water to rest either overnight or for around 7-8 hours if you’re performing your Chlorine shock dose during the day.

7: Test levels.

Coming back to your Lay Z Spa hot tub, you’ll need to check that the bromine or chlorine you’ve added has settled to the correct level before the water will be safe to bathe in.

This is best achieved with hot tub water testing equipment, which for either chemical will give you a visual reading of how much sanitiser is currently dissolved in the water.

With Clearwater chlorine, you’ll be looking for a reading of 3-5  parts per million (ppm). For bromine, you’re looking for 2-6 ppm. If the sanitiser level is too high, you’ll need to wait at least 30 minutes before retesting the water until the level is correct.

8: Enjoy your clean water!

With your Lay Z Spa’s chemicals at a safe level, you’ll now be ready to enjoy a relaxing soak with others.

A single spa Chlorine shock dose should last around 2 weeks, though experts recommend performing a shock dose once a week if you’re using your Lay Z Spa on a daily basis.

If you notice cloudy water, the water starts to smell, or you’ve recently enjoyed a period of heavy usage, you can be pretty sure it’s time for a new spa shock treatment! 

If you prefer visual instructions, this video shows how to easily shock a Lay Z Spa

When Should You Use A Hot Tub Shock Treatment

Using for the first time

All new Lay Z Spas will need a Chlorine shock dose and fresh sanitiser treatment before they’re safe to use, as this will actively protect you and your guests from bacteria and germs, as well as remove any organic waste in the water.

If you see signs of algae

Algae spores can bloom rapidly, so to save yourself a lot of time draining, refilling and cleaning your Lay Z Spa, it’s best to nip the problem in the bud!

Clearwater Chlorine-based shock treatments are the best way to remove organic contaminants, as the increased levels of free chlorine in the water will kill any spores pretty quickly and prevent them from coming back.

When you’ve been using the spa a lot

The more you use your Lay Z Spa and the more people you have in your hot tub, the amount of organic waste and bacteria will increase.

Humans deposit skin cells, hair, residue from lotions and shampoos and even live bacteria into the water as they bathe, so to prevent these contaminants from dirtying your hot tub, it’s best to maintain a healthy bromine or chlorine level.

When refilling after cleaning or storage

Refilling, cleaning or packing away your Lay Z Spa hot tub for an extended period of time will result in losing the chemically treated water or the chemicals that were present, losing their ability to work correctly.

This means you’ll need to start from scratch with your pH balancing routine, which is best done by performing a bromine or chlorine shock treatment, and then maintaining your chlorine or bromine level by using the appropriate sanitiser in tablet form. 

Poor water quality

If your hot tub water is beginning to look a little cloudy, or there are obvious signs of grime and organic growth, you can be pretty sure that it’s time for a Chlorine shock dose!

You should always aim to keep your hot tub water clear, and regularly check your pH level to be sure that the water is safe. Checking your chlorine level in your hot tub can also be useful when dealing with cloudy water as too much chlorine can cause this issue! 

If the chlorine level in your hot tub is too high, you can simply leave your Lay Z Spa uncovered for a few hours to allow the chemical to naturally dissipate.

How It Works

an owner shocking their hot tub

Shocking your Lay Z Spa hot tub is the most effective way of removing bacteria, germs and organic compounds that have built up in the water.

All hot tubs rely on chemical sanitisers to keep the water clean, but these chemicals lose their potency over time, and some contaminants and germs will begin to build up. 

A large dose of your chosen sanitiser added to the water at once kills bacteria and germs very effectively and allows you to reset your chemical levels again for another week or two of safe hot tub bliss! 

How Often Should I Shock The Hot Tub Water?

Most expert’s advice and experience agree that regardless of how often you use your hot tub, a shock dose will be required to maintain a healthy chemical balance at least once every two weeks.

If you’re using your Lay Z Spa hot tub daily, you’ll need to up that routine to once every week, and remember that just because the hot tub water looks clean, it isn’t necessarily free from microscopic germs and bacteria! Things like that are always there even if unseen to the eye, That’s why it’s essential to test the water and do weekly shocking to keep your Bestway Lay Z Spa free of germs and the hot tubs chemicals at the recommended levels. 

Lay Z Spa Shock Dose:

A good rule to stick to when measuring your shock dosage is to use about one teaspoon (5g) of sanitiser granules for every 250-300L of hot water tub holds.

This is in line with Clearwater Chemicals’ recommendations, which are specifically designed for treating Lay Z Spa hot tubs whatever the water type. We’ve compiled a handy list of suitable dosages for most Lay Z Spa models below but always check the instructions before shocking your spa water 

Water Capacity (Litres) Lay Z Spa Models How Many Grams of Chlorine Teaspoons 1 = 5g
605L St Lucia spa, Aruba spa 5 1
669L Bali spa, Havana spa, Tahiti spa, Cancun spa, Zurich spa, Bahamas spa, Fiji spa, Madrid spa, Barbados spa 6 1
778L Ibiza spa 7 1
795L Hawaii spa, Majorca spa 7 1
800L Miami spa 7 1
804L Singapore spa, Vancouver spa 7 1
806L New York spa, Paris spa 8 2
840L Hawaii spa 8 2
848L Vegas spa 8 2
916L Honolulu spa, Milan spa, Palm Springs spa 8 2
1050L Maldives spa, Palma spa 9 2
1123L Helsinki spa 10 2
1190L St Moritz spa, Santorini spa 11 2
1350L Grenada spa 12 2
1370L Mauritius spa 10 2

Lay-Z Spa Chemicals Instructions

Though the best chemicals used for shock treatments are safe when dissolved and have many benefits, they can cause burns and skin damage when handled in their pure form, so always grab a pair of gloves before shock dosing! We’d recommend something like all in one hot tub chemicals instead of multiple products.

Always perform chlorine shock and non-chlorine shock treatments in a well-ventilated area with your Lay Z Spa’s hot tub cover removed. These shock chemicals can release toxic gasses, which can be harmful if inhaled. It’s also best to avoid strong winds as the granules can be blown into your face when you add chemicals. 

Never mix chemicals as they can cause dangerous chemical reactions, and always add chemicals to a larger body of water, never the other way around!

It’s also essential to wait for levels to be restored before jumping into the spa after a shock treatment 

Finally, always store hot tub chemicals in a cool, dry place, out of reach from any children or pets. These shock treatment substances are sensitive to heat and moisture and harmful if ingested, so we recommend storing in a lockable container.


Can I use my Lay Z Spa without chemicals?

Can you over shock a hot tub?

Last Word

So, that’s it! We hope you’ve learned that it’s not too tricky to shock your Lay Z Spa, whether you are using standard shock dosing methods or a non Chlorine shock treatment and as long as you’re performing a hot tub shock dose at least twice a month, you shouldn’t have to worry about any nasties ruining your hot tub fun!

Remember to use the chemical granules or Chlorine tablets that correlate to your hot tub sanitiser, when shock dosing and always add your chemicals to water, not the other way around!

Make sure to test the water daily with test strips, and if you do over-shock your spa, just allow the chemicals to dissipate naturally in a well-ventilated area to restore Chlorine levels, but most of all, we hope you enjoy your next soak! 

John Devlin

Hello, Welcome to my website. I’m John, and I created the InflatableHotTubGuide while researching these spas nearly a decade ago. Since its creation, the site has become the leading UK resource for many models. As a passionate hot tub user, I love to test and explore all the latest machines this industry keeps creating. I hope you find our content helpful.